| 摘要 |
PURPOSE:To prevent deformation or breakdown of battery by providing porous material having air or oxygen gas permeation rate higher than 68cc/h per 1 Ah in exhausting direction while lower than 0.02cc/h in sucking direction. CONSTITUTION:Porous member 1 having gas permeability is made of resilient material and mounted over a exhaust hole 3 of cover 2 then stopped by a stopper board 4 having a hole 5 larger than the exhaust hole 3. Consequently, the porous member 1 is easily deformed by inner pressure rise of battery but hard to be deformed by reduction of inner pressure. While the porous member 1 has the oxygen gas permeation rate in exhausting direction higher than 68cc/h per nominal capacity of 1 Ah while lower than 0.02cc/h in sucking direction. Consequently, deformation or breakdown of battery can be prevented. |
